This salsa is also delicious on top of grilled hamburgers or chicken.
In a food processor, puree plum tomatoes, jalapeno, lime juice, and cumin; transfer to a small bowl. Stir in yellow and sun-dried tomatoes. Season with salt and pepper.
Just before serving, drain off any accumulated liquid, and stir in oil from sun-dried tomatoes.
Heat grill to medium-high; lightly oil grates. Season steaks with salt and pepper. Place on grill; cover. Cook, turning once, about 8 minutes for medium-rare. Top with tomato salsa and serve.
Core, then halve tomatoes lengthwise. Using a small spoon, scrape out and discard seeds, liquid, and pulp, leaving only the tomatoes outer flesh.